Reproducer.



'I'. A. EDISON.

REPRODUCER.

APPLICATION FILED MAY 18, 1911.

ljygl a Patented Mar.11,1913.

UNTTnn sTaTns TATTNT carros.

THOMAS A. EDISON, 0E WEST ORANGE, NEW JERSEY, ASSIGNOR TO THOMAS A. EDISON, INCORPORATED, OIF WEST ORANGE, NEW JERSEY, A CORPORATION 0F NEW JERSEY.

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Specification of Letters latent.

Application led May 18, 1911.

Patented naar. ii, iets..

Serial No. 627,952.

My invention relates to. reproducers for lph'onographs and other sound reproducing .apparatus and myprincipal object 1s to provide'. ade'vice of this character whereby an improved .quality of reproduction can be obtained.v

It has heretofore been customary to conneet thel tail of the stylus lever to the diaphragm by means of a rigid metal link. rlhis structure is objectionable in that the diaphragm cannot move quickly enough to permit the stylus toremain 1n engagement with therecord groove so that the stylus jumps over the forward walls of the deep indentations and after striking the bottom of the indentations rebounds from the rec. ord and causes the production of sharp unpleasant sounds. Slight defectsin the record furthermore cause the transmission to the' diaphragm of objectionable weak sounds, and the suddenness o r abruptness of the sound waves causes the emission of sharp metallic sounds. Furthermore itis impossible to form a metallic connecting link perfectly straight; and as the weight used with reprodueers is never suilicient to straighten out the flat howcommonl'y found in such a link, the vibration of the stylus lever producesv therein local vibrations whereby the loudness and accuracy of the reproduction are greatly impaired.

1I have-found that the 'above defects may be remedied by employing an elastic resilient connection, such as a cotton string to connect the stylus lever to the diaphragm. SuchV a connection is of very small weight, and therefore responds readily to the elastic power stored therein to hold the stylus continuously in engagement with the record groove. It also through ,its short elasticity absorbs the objectionable weak sounds mentioned above and diminishes the suddenness and abruptness of the sound waves so that a very pleasing mellow tone is obtained. By, choosing ya connection of proper elasticity and diameter, and properly adjusting the length thereof, the quality ofthe reproduction may obviously be varied at will. As

La weight of small mass is sufficient to hold my improved connection taut, the objections due to the curved form of metal linksv are eliminated.

My invention furthermore comprises an improved diaphragm of such lightness and flexibility that the weight of the reproducer and the consequent wear on the recordcan be materially decreased.

Other features of my invention are an improved connection between the diaphragm and stylus lever whereby the dis- .tortipn ofthe diaphragm during the reproduction of the record' is prevented, and an improved mounting for the stylus lever wherebymthe same is caused to more readily and faithfully track'the record groove.

Further objects of my invention will 'a'ppear more fully in the following specication and appended claims.

In order that my invention may be better understood, attention is hereby directed to the accompanying ,drawings forming part of this specification and in whichv Figure lis a side elevation partly in section showing a reproducer embodyingmy invention; Fig. 2 is a bottom plan View thereof; Fig. 3 is a front elevation showing a .detail of construct-ion; Fig. 4 is anY enlarged central vertical section showing another detail of construction; Fig. 5 is a view similar to that shown in Fig. 4 of a modification; and Fig. 6 is a side elevation of another modiiicatlon. j

In all the views, like parts are designated by the same reference numerals.

The sound box comprises an annular member 1 having an extension 1 and an upper conical member 2 provided with a neck 2', the periphery of the member 2 being secured between two rings 3 and '4, threaded into the interior of thel annulus 1.' The diaphragm 5 is mounted between rubber gaskets 6 and 7 which in turn are secured between the ring 4 and a third ring 8 threaded into the bottom of the member 1. The stylus 9 is mounted in a lever 10 rotatably supported on a pivot 11 which is mounted at its ends in spaced bearings 12 .projecting downwardly from the lower surface of the weight f13. In order to prevent the record from throwing the stylus lever and stylus sideloo c, arm of the lever is long, a suiiicient width being preferably obtained for the bearing by providing the lever with laterally, oiset or projecting portions through which the pivot 11 passes, as shown. As clearly lshown in Figs. l and 2, I make the weight 13 of considerable length and mount the same at a considerable distance from the place at which the stylus lever is secured thereto,-

thus providing a t structure wherein the pivotal movement of thel floating weight in following the irregularities of the record is very'slight; so that the said weight, by reason of the increased leverage obtained, is

readily adjusted by the stylus in tracking u floating weight is the record groove. Th connected tothe outer e d of the extension 1 rin the following manner: A spring 14 or' other suitable elastic member is secured atA its forward end by'means of screws 15 to the rear end of th e weight .13, washers 16 being inserted between the heads of the said screws and the spring 14. At its opposite end, the spring 14 is secured by screws 17 to a. headed pivot member 18l loosely swiveled 'in abvertical opening in the outer end of the extension 1. l The numeral ,19 represents -washersl inserted between the screws 17 andthe head ofthe member 18, and the numeral 20 a nut for securing the Lpivot member 18 in place. The swiveling or pivoting of the floating weight as described above permits lthe stylus to track close to the center of the `record groove and 'thus eliminates objectionable pressure on the sides of the record groove.

The elastic sprin "connection described above is evidently ee from objectionable looseness such as is practically unavoidable in the ordinary pivot joints employed for mounting floating weights, it belng practically veryditlicult to make a small pivotal connection tight without binding.

Secured to the front of the floating weight, is a loop 21 having an upper portion 2,2 in the shape of an inverted V, this latter portion ybeing adapted to be rengaged by a pin 22 secured to the front of the member 1' to center and support the floating `weight when the reproducer is raised from operative position. l

The diaphragm 5 is made of a very light and flexible material so that it is possible to reduce the weight on the stylus and thus diminish the wear on the record and I cause a more faithful production from the record. The body portion of the diaphragm is preferably built up of a number o-f layers of elastic fibrous. material, sheets 23.

of Japanese paper about .001 of an inch thick being preferably employed. These sheets are thinly lacquered,l then placed'in -the air to dry,'then assembled together to for a diaphragm two inches in diameter is .005 of an inch. To this body portion is secured by shellac or other suitable means, a

center piece 24 of cork or other suitable elastic yielding material. This Vcenter piece 2'4 is made comparatively thick at the center, tapers oi toward its edge, and covers a large portion of the area of the diaphragm. .For a diaphragm vtwo inches in diameter, I have found that the `center piece should be about one-eighth of an inch thick at the center, and about one and one-half inches'in diameter. The curvature of the outer surface of the center piece 24 should be such that substantially the whole body portion of the diaphragm exes into a spherical shape during the vibration thereof by the stylus.

Such a diaphragm as described above not only has elasticity as a whole, but it is made of a material which is internally highly elastic, thus requiring a minimum of power to set it in motion. .The diaphragm is further advantageous as it is stable and does not change with use, the whole diaphragm being extremely light in weight compared with those in general use, and being at the same time by reason of the em ployment of the relatively thick center piece free from strains' which permit local buckling when vibrations of great amplitude are emitted.

Another improvement contemplated by my invention is the substitution of an elastic, resilient, noni-metallic member, such as a cotton cord 25, for the commonly employed metallic connecting link between the stylus lever and the diaphragm. This cord, as shown in the drawing, is connected at its ends by light fiexible wires 26 and 27 or other suitable means to the tail of the stylus lever 10 and to the link 28 respectively. The link 28 its closely in a vertical opening in a lcup shaped cap or bridging member 29 which issecured to the upper face of the diaphragm by shellac or any other suitable means 'and extends across and aSubStantial distance above the central opening 29 provided in the diaphragm, a similar opening being formed in the cork member 24 imme-l diately below the opening 29'.

bAs shown in Fig. 1, the upper portion of wire 27 is connected for universal movement to the lower portion of the link T28 substantially at the center of the diaphragm 5. By the term center as herein em loyed with referencegto the diaphragm, mean the point on the central axis of t-he diaphragm.

midway betweenthe faces vof the body ortion of thediaphragm. With the constiuc# tion herein disclosed-the center of the diaphragm will be located midway between the extremitiesiofthe, opening 29.). By connoa-etai so that there is no local compressionl of the said member or the diaphragm and no loss of amplitude in the vibration.

As .hereinbefore stated, the employment of an elastic resilient non-metallic connection such as the cord 25 for transmitting the vibrations of the stylus lever to the diaphragm serves as a 'means of niellowing the tone of the diaphragm and improving the quality of the reproduction, the quality being read.

ily controlled by using a connection of suitable diameter and elasticity and by properly adjusting the length of the connection. Such` a connection is sufficiently light to respond rapidly to the elastic power stored therein by the floating weight and thereby causes vthe stylus to 4more accurately track the record groove than if the same were joined to the relatively slowly moving diaphragm by .a rigid connection. In my invention as above disclosed, both the diaphragm and the connection 25 serve through the tension im- 'parted thereto by the floating weight to hold the stylus inengagement with the record, so that a very faithful reproduction is obtained.

ln Fig. 5, l have shown a modifiedmeans for connecting the cord 25 to the diaphragm. A piece of wire bent to form a loop 30 at its lower end, is twisted as shown at 31 and passed through the vertical opening in the cap 29, being then bent down upon the topl of the capas shown at 32. The loop 30 is ofv suficient size to bear upon the lower surface of the cap 29, and the upper portion- 32 of the wire is secured to the top of the cap by a mass 33 of shellac in which the said upper portion is embedded. A ring 34 gripping the upper end of the cord 25 therein is suspended from the loop 30 by a wire loop 35 which passes through the loop 30 and is secured at its ends to the sides of the ring 34.

In Fig.y 6, l have shown a vertically disposed sound box 36, having a stylus lever 37 pivoted toears or lugs 38 projecting from the side of the sound box, the lever being' an odset portion 39 support- 40 and extending underthe With this construction, lthe provided with ing the stylus sound box.

weight of the sound box 'holds the elastic4 resilient cord 25 under tension and thereby causes the stylus to accurately track the.,

` record. y Y

Many modifications, in addition to those described above, may be'made in' my invention, and I wish, therefore, not to be limited to the exact details shown and described.

What l claim `as new and desire to protect by United States Letters Patent is as follows:

phragm -composed of a plurality of supera unit-ary structure, substantially as described.

2. As an article of manufacture, a diaphragm composed of a plurality of superposed sheets of Japanese paper united into a unitary structure having secured thereto an elastic yielding member located concentrically with one of the faces of the said structure, and extending into proximity to the periphery thereof, the said elastic member being of decreasing thickness from the -center to the periphery thereof, substantially as described..

3. In a device of the class described, the combination of a diaphragm, a support therefor, a floating weight, a stylus lever supported thereby, means for connecting said stylus lever to said diaphragm, and resilient means-for securing said weight t'o said support, said weight being arranged to place said connecting means normally under tension substantially as described.

4:. in a device of the class described, the combination with a diaphragm, a support therefor, a o-ating weight, a stylus lever mounted on said floating weight, means for connectingl said lever to said diaphragm,

- and resilient means for connecting said weight to said support, said last named means being mounted to permit lateral -movement of said floating weight, substantially as described.

5 In a device of the class described, the

therefor, a oating weight, a stylus lever supported thereby, 'means for connecting said stylus lever to said diaphragmyand means comprising a iat spring for securing said weight to sald support, said weight being arranged to place said connecting means normally under tension substantially as described.

6. ln a device of the class described, the combination of a diaphragm having a central opening therein, a member separate from said diaphragm, mounted thereon, and forming a bridge across and at a substantial distance above said opening, securing means connected to said member and extending into said opening, a stylus lever, and con- `necting means between said securing means and said stylus lever, said-connecting means being connected to said, securing means at the Acenter of said diaphragm, substantially. as described.` i

1. As an article of manufacture, a dial posed sheets of Japanese paper united into combination of a diaphragm, a support 7. In a device of the class described, the' combination of a diaphragm having a cen'- tral opening therein, a 'member separate from said diaphragm, mountedl thereon, and forming a bridge across and at a substantial distance above saidv opening, securing means connected to said member and extending into said opening, a stylus lever mounted for movement laterally of as well as toward' and away from said diaphragm, and connecting meansA between said securingmeans and said stylus lever, said connecting means being connected to said securing means at vthe center of said diaphragm and having universal movement with respect to said se curing means, substantially as described.

8. In a device of the class described, the combination of a diaphragm having a central opening therein, a member separate from said diaphragm, mounted thereon,l and forming a bridge 4across and at a substantialA 1 distance above said opening, securing means connected to said member and extending into said opening, a stylus lever, and elastic non-metallic connecting means between said. securing means and said stylus lever, said connecting means being connected to said securing means at the center of said diaphragm, substantially as described.

9. As an article of manufacture, a diaphragm having a body portion composed of `Japanese paper and a center piece of elastic material secured to oneface of said body portion and having a diameter greater'than one-half the diameter of said diaphragm, substantially as described.

10. As an article of manufacture, a dia-v phragm having a body portion composed of Japanese paper anda center piece of cork secured to one face of said body portion and Vhaving a diameter rreater than one-half the l diameter of vsaid iaphragm, substantially as described.

11. -In a device of the class described, the combination of a diaphragm, a support therefor having an extension thereon, anV elongated floating Weight, a stylus lever supported thereby, means for connecting said stylus lever to said diaphragm, and resilient supporting means having connections to said support and Weight, said, con- -nections permitting lateral movement of said weight., substantially as described.

12. In a device of theclass described, the

combination with, a diaphragm, a support therefor, a floating weight, a' stylus lever 'having a horizontal bearing of considerable width relative to the length of the tracking arm of the lever mounted on said floating weight, means for connecting said lever to said diaphragm and resilient means for. coI1- necting said weight to said support, said means being 'mounted to permit. lateral this 16th day of May 19H11.

than one-half .the diameterfof said diaphragm, substantially as described.

formed of Japanese paper, sub- 15. Asv an article of manufacture, a vdiaphragm having a body portion composed of elast-ic non-subereous material and a center piece of `cork secured to one face of said body portion and having a diameter greater than one-half the diameter of said diaphragm, the said center piece being of decreasmg thickness from the center to the periphery thereof, substantially as described.

16. As an article of manufacture, a diaphragm having av body portion composed of .a plurality of superposed sheets of elastic' material united into a unitary structure and a member of cork located .concentrically with one of the .faces of the body portion and extending into proximity tothe periphery'thereof, substantially as described.

v17. In a device of the class described, the combination of a diaphragm, a support therefor, a floating weight, a stylus lever supported thereby, resilient non-metallic means for connecting said stylus lever to said diaphragm, and resilient means for securing said weight to said support, said weight being arranged to place said c011- necting means normally under tension, substantially as described.

18. In a device of the class described, the combination of a diaphragm, a support therefor, a floating weight, a' stylus lever supported thereby, means for connecting said stylus lever tosaid diaphragm, andresilient means for securing said weight to said support, said Weight being movable upwardly and downwardly and being arranged to place said'co'nnecting. means normally under tension, substantially as described. v 2

19. As a new article of'manufacture, a

v diaphragm of elast-ic-.materiaLhaving a cen- 'tral opening therein, and an ivory bridging member mounted on said diaphragm above- 'said opening, substantially as described.

This specification signed and witnessed THGMAS A EDISON.

WVi-tnesses: A l FREDERICK BACHMANN, l

ANNA R. KLEHM. 

